The present invention relates to a motor drive controller for a vehicle and, especially, to a motor drive controller receiving respective detection signals from a vehicle velocity detector and an engine speed detector to determination of the gear position; furthermore, said motor drive controller makes use of the smallest number of sensors that still allows detection of gear position, resulting in a simplified system and reduced production costs.
Some motor vehicles are of a type commonly called a hybrid vehicle having an internal combustion engine and an electric motor disposed therein as the power sources of a propulsion system. The hybrid vehicle further includes an engine controller for controlling a running state of the engine and motor controller for controlling an operating state of the motor. The engine controller and the motor controller detect respective operating states of the engine and the motor when the vehicle is traveling, and then exchange such detected data regarding the running states. As a result, the respective operating states of the engine and the motor are controlled in association with one another. Such a control system attains a high level of required performance (such as fuel efficiency, lower values of detrimental components in exhaust gases, and power performance).
One such example of a vehicle controller is disclosed in published Japanese Patent Application Laid-Open No. 5-322032. The clutch switch failure detection system indicated in this disclosure uses the vehicle velocity and engine speed to determine gear position in the transmission, and from the change in gear position measures the number of shifts, and by matching the number of measured shifts with the number of changes in the signals from the clutch switch, it is able to determine if there is a clutch switch failure and detects such clutch switch failure efficiently.
Also, there is something germane in published Japanese Patent Application Laid-Open No. 8-182109. In the running mode control system of an electric powered vehicle in this disclosure there is a transmission mounted between the vehicle running mode motor and the drive wheel, wherein, as a running mode control system, the transmission control means depends on the shift position, such that, if the shift position exhibits advance, retreat, or neutrality at the same time that a brake demand is being emitted, the response is to use the drive wheel as a regenerative braking means; if, when the shift position exhibits neutrality and there is not a brake demand being emitted, there is a means whereby the power supply to the vehicle running mode motor is shut off, making the regeneration of the vehicle""s running energy more possible.
Also, there is something germane in published Japanese Patent Application Laid-Open No. 9-89090. In the synchronous control system of a vehicle in this disclosure, there is a synchronizing mechanism, an electric motor connected with the transmission system""s input shaft, a transmission operation detection means which detects whether the lever is at a specified reserve position that it must pass through on its way to a specified gear position, an input shaft detection means which detects the speed of the transmission input shaft, and a control system. When the transmission operation detection means detects that the lever is at a specified reserve position that it must pass through on its way to a specified gear position the speed that the input shaft should reach after shifting gears is predicted based on the input shaft speed and gear ratio, and while the clutch is disengaged an electric motor is controlled synchronically to ensure that the input shaft speed reaches the speed that was predicted, thus increasing the durability of the synchronizing mechanism.
Also, there is something germane in published Japanese Patent Application Laid-Open No. 9-93724. The electric powered vehicle in this disclosure includes a transmission that has at least two alternatively chosen steps, an output axle that is connected to the vehicle""s drive wheels via the transmission, an electric motor that is connected electronically to the battery mounted on the vehicle, a driving condition detection means which includes a transmission location detector that detects the transmission steps, and an accelerator opening detection means that detects the accelerator opening. Based on the respective detection data received from the transmission location detector and the accelerator opening detector, there is a control means whereby the drive power generated at the drive wheel is made equal before and after the transmission operations at an equal accelerator opening, by controlling the torque generated in the electric motor in response to the accelerator opening.
Also, there is something germane in published Japanese Patent Application Laid-Open No. 9-191 507. The electric powered vehicle in this disclosure includes a control means such that in an electrically driven vehicle that has a transmission disposed between the motor and drive wheels, when the halt-detection means detects that the vehicle is actually in a halted condition, and the shift-change detection means detects a change from the D-range or the R-range to the N-range or the P-range, the torque-command-value diminishing means directs the torque command value to gradually approach zero, thus reducing the surface pressure on the gear teeth in the transmission and preventing the striking noises that occur when the gears undergo a backlash.
Also, there is something germane in published Japanese Patent Application Laid-Open No. 10-201013. The electric powered vehicle in this disclosure includes a motor control system that includes a target torque setting means that sets the target output torque level for the running motor based on the amount of accelerator operation, and also includes a motor torque control means which controls the running motor output torque in response to the target output torque level set by the target torque setting means. The target torque setting means includes a target torque setting corrective means whereby when the motor speed drops below a predetermined value the target torque is increased and corrected, depending on the motor speed, by an increase and corrective ratio or an increase and corrective quantity. This increase and corrective ratio or increase and corrective quantity is set to become larger as the motor speed drops and smaller as the motor speed rises, thus lessening the load on the acceleration operation during vehicle starts and accelerations as well as allowing more fine-tuned accelerator work.
In the control means of a so-called hybrid vehicle controller heretofore employed, when detecting the gear position in the transmission, detection was made by a gear position sensor for each position. Then, various control operations were carried out using the detection signals provided by said gear position sensors. However, installing gear position detection sensors for every gear in said transmission results in complicated construction, difficulties in manufacture, practical inconveniences, and high costs.
In order to obviate the above inconveniences, the present invention provides a motor drive controller for a vehicle having an engine and a motor disposed therein as a vehicle-propulsion system, the motor having both driving and power-generating functions, comprising: an engine controller for controlling a running state of the engine; motor controller for controlling both driving and power-generating states of the motor in a manner independent of control over the engine taken by the engine controller; vehicle velocity-detector for detecting velocity of said vehicle, engine speed-detector for detecting revolution of the engine; and, engine load-detector for detecting engine load, wherein the motor controller includes a map defined by respective detection signals from the vehicle velocity-detector and from the engine speed-detector, the map to be used in calculating gear position.
According to the present invention, the motor controller has a function whereby respective detected signals from the vehicle velocity-detector and from the engine speed-detector are used to calculate gear position, and a fewest number of sensors will be used to detect gear position. Accordingly, construction will be simplified and costs will be reduced.